"to our sister republics south of our border, we offer a special pledge: to convert our good words into good deeds, in a new alliance for progress; to assist free men and free governments in casting off the chains of poverty. (but this peaceful revolution of hope cannot become the prey of hostile powers.) let all our neighbors know that we shall join with them to oppose aggression or subversion anywhere in the americas. and let every other power know that this hemisphere intends to remain the master of its own house." the sentence in parenthesis in the selection above signifies a shift in tone. which sentence below best explains kennedy's tone before the shift? a: he is offering to friendly and democratic nations in our part of the world. his tone is promising. b: he is stating that the united states will support people and governments in the americas. his tone is regretful. c: he is suggesting that other countries are poor. his tone is sorrowful. d: he is warning other countries that the united states will support peaceful revolutions. his tone is threatening.